Generally, arc gap switches or spark gap switches are used as switches for high voltage, high current pulses, which typical semiconductor switches have trouble enduring. These switches should ensure controllability while withstanding voltages of several tens of kilovolts and should have regular operating characteristics under varying ambient operating conditions. Especially, since high current pulses passing through the switches have high temperature arcs, which create temperatures of tens of thousands of degrees Celsius such as that present in a bolt of lightning, the switches should have an operational principle and structure being made of special materials such that electrode damage can be prevented. Additionally, the size, durability, maintenance, and cost of the switches must be taken into account.
Meanwhile, conventional switches for handling high current pulses employ various principles and methods. Such high current switches include, among others, an ignitron type, an inverse pinch type, a pseudo spark gap type, a triggered vacuum type, and a rotary arc type. Although the above switch types exhibit different characteristics and each have their own advantages and disadvantages, none of the conventional switches satisfy all of the above-mentioned requirements.
The conventional switches are especially problematic in terms of a limited lifetime over which controllability and stable operating characteristics can be ensured, which in turn limits utility. These problems are mainly caused by a deterioration of the operating characteristics or a functional loss of the switches, due to electrode burnout or insulation breakdown, which results in the catastrophic failure of the switch.